New technologies have allowed us to image the immune response in vivo in 3 spatial dimensions as well as time. The rodent eye is ideal for in vivo imaging of the immune response. The eye is a well recognized target of immune-mediated inflammation known as uveitis. We have succeeded in imaging leukocyte-endothelial interactions in the inflamed mouse and rat eye in a system that involves no surgical trauma and which allows repetitive observation over many days. Using the technique of ocular intravital microscopy, we propose to: 1) determine the role of antigen specific T cells in immune-mediated or autoimmune inflammation; 2) determine the role of specific adhesion molecules or cytokines in an in vivo model of immune-mediated inflammation; 3) identify the site and kinetics of T cell activation in vivo in a disease model; and 4) enhance the technology that we are currently using to obtain 4 dimensional imaging of the immune response. These studies offer a unique opportunity to develop modalities to image the immune response in vivo.